a) Field of the Invention
The invention is directed to a microscope in which laser light is used to irradiate a sample to be examined and which is outfitted with a protective device for preventing eye damage due to laser light.
b) Description of the Related Art
When using laser light for microscopy, special protective measures must be undertaken in order to protect the user's vision. This is particularly true for TIRF microscopy (TIRF=Total Internal Reflection Fluorescence) because it uses relatively intensive laser radiation.
It is known from U.S. Pat. No. 5,850,038, for example, to place shutters in the microscope beam path which are coupled with the operating state of the laser and which prevent the laser radiation from reaching the observer's eye through the eyepieces.
Further, it is common for housing covers on optical devices operating with laser radiation to be provided with warning signs so as to draw attention to the danger subjectively. Safety regulations specify that the housing covers may only be opened with tools. However, the prerequisite of using tools to access microscope samples is disadvantageous and obstructive.
Completely enclosing a microscope operating with laser light with an opaque enclosure that protects the user is likewise disadvantageous because the sample space is difficult to access and the sample cannot be viewed.
A laser protection hood which encloses the sample space and is made of material that is not transparent to laser radiation is known. In this way, the laser radiation is completely blocked and does not reach the eyes of the user. This laser protection hood has a cover which is likewise opaque to laser radiation and which is articulated by hinges and provided with closing contacts which communicate with control electronics.
When the cover and, therefore, the contact are opened, the control electronics ensure that a shutter arranged in the laser beam path is switched on so as to block the propagation of the laser radiation.
In this way, an active laser protection is realized for the entire visible spectral region of the light coming from the laser. However, this likewise has the disadvantage that the sample is completely invisible to the user.